The gearcase of an outboard engine of a boat is often provided with an anti-ventilation (AV) plate, which is also sometimes referred to as an anti-cavitation plate or a cavitation plate. The AV plate, which extends horizontally and rearward from the gearcase above the propeller, is intended to prevent surface air from being sucked down into the rotating propeller. The AV plate can also provide some measure of splash protection to the engine extending thereabove and the interior of the boat against the water being sprayed by the rotating propeller. Additional flanges extending rearwards from the gearcase or the midsection of the engine may also be provided.
It is known to adapt the AV plate to other functions by either modifying the plate itself or by attaching hydrodynamic elements to/near the AV plate. For example, U.S. Pat. No. 2,564,903, issued Aug. 21, 1951 to Irgens, describes an AV plate that doubles as a trim tab having angled surfaces to provide lift. Other examples of hydrodynamic elements that have been provided on or near an AV plate include hydrofoil wings of various kinds for generating lift, pivotable fins to compensate for torque created by the propeller, and trolling plates.
These structures are typically attached to the AV plate by bolts extending vertically through the horizontally extending AV plate. The installation of the structures on the AV plate may require access to the space between the AV plate and the propeller, and the structures may also need to be held to the AV plate by other means while they are being positioned thereon and fastened thereto.
It is desirable to have a quick, easy and reliable attachment system for installation of hydrodynamic structures and other accessories on an outboard engine. It is also desirable to have an attachment system that is versatile and able to receive different kinds of accessories.